package model

import (
	"time"

	"gorm.io/gorm"
)

// Device status constants
const (
	DeviceStatusOnline    = "online"
	DeviceStatusOffline   = "offline"
	DeviceStatusUpgrading = "upgrading"
)

// Deployment status constants
const (
	DeploymentStatusDraft     = "draft"
	DeploymentStatusActive    = "active"
	DeploymentStatusPaused    = "paused"
	DeploymentStatusCompleted = "completed"
	DeploymentStatusCancelled = "cancelled"
)

// Deployment device status constants
const (
	DeployDeviceStatusPending     = "pending"
	DeployDeviceStatusDownloading = "downloading"
	DeployDeviceStatusDownloaded  = "downloaded"
	DeployDeviceStatusVerifying   = "verifying"
	DeployDeviceStatusInstalling  = "installing"
	DeployDeviceStatusCompleted   = "completed"
	DeployDeviceStatusFailed      = "failed"
	DeployDeviceStatusRolledBack  = "rolled_back"
)

// Rollout strategy constants
const (
	RolloutImmediate = "immediate"
	RolloutStaged    = "staged"
)

// Target type constants
const (
	TargetAll    = "all"
	TargetDevice = "device"
	TargetGroup  = "group"
)

// Device represents a connected daemon instance.
type Device struct {
	ID             int64     `json:"id"              gorm:"primaryKey;autoIncrement"`
	DeviceID       string    `json:"deviceId"        gorm:"uniqueIndex;size:256;not null"`
	IPAddress      string    `json:"ipAddress"       gorm:"size:64;default:''"`
	Hostname       string    `json:"hostname"        gorm:"size:256;default:''"`
	OS             string    `json:"os"              gorm:"size:64;default:''"`
	CurrentVersion string    `json:"currentVersion"  gorm:"size:128;default:'0.0.0'"`
	Status         string    `json:"status"          gorm:"size:32;default:'online';index"`
	GroupName      string    `json:"groupName"       gorm:"size:128;default:'default';index"`
	LastHeartbeat  time.Time `json:"lastHeartbeat"`
	CreatedAt      time.Time `json:"createdAt"`
	UpdatedAt      time.Time `json:"updatedAt"`
}

// Artefact represents an uploaded update package (JAR or patch).
type Artefact struct {
	ID         int64     `json:"id"          gorm:"primaryKey;autoIncrement"`
	Version    string    `json:"version"     gorm:"size:128;not null;index"`
	FileName   string    `json:"fileName"    gorm:"size:512;not null"`
	FilePath   string    `json:"-"           gorm:"size:1024;not null"`
	FileSize   int64     `json:"fileSize"`
	SHA256Hash string    `json:"sha256Hash"  gorm:"size:128"`
	DeltaRef   string    `json:"deltaRef"    gorm:"size:128;default:''"`
	IsDelta    bool      `json:"isDelta"`
	Metadata   string    `json:"metadata"    gorm:"type:text;default:'{}'"`
	CreatedAt  time.Time `json:"createdAt"`
}

// Deployment defines an update rollout campaign.
type Deployment struct {
	ID              int64     `json:"id"               gorm:"primaryKey;autoIncrement"`
	ArtefactID      int64     `json:"artefactId"       gorm:"not null;index"`
	Artefact        *Artefact `json:"artefact,omitempty" gorm:"foreignKey:ArtefactID"`
	Name            string    `json:"name"             gorm:"size:256;not null"`
	Description     string    `json:"description"      gorm:"type:text;default:''"`
	TargetType      string    `json:"targetType"       gorm:"size:32;default:'all'"`
	TargetSpec      string    `json:"targetSpec"       gorm:"type:text;default:'{}'"`
	RolloutStrategy string    `json:"rolloutStrategy"  gorm:"size:32;default:'immediate'"`
	MaxConcurrent   int       `json:"maxConcurrent"    gorm:"default:50"`
	Status          string    `json:"status"           gorm:"size:32;default:'draft';index"`
	CreatedAt       time.Time `json:"createdAt"`
	UpdatedAt       time.Time `json:"updatedAt"`
}

// DeploymentDevice tracks an individual device's progress through a deployment.
type DeploymentDevice struct {
	ID           int64      `json:"id"            gorm:"primaryKey;autoIncrement"`
	DeploymentID int64      `json:"deploymentId"  gorm:"not null;uniqueIndex:idx_dd_dep_dev;index"`
	DeviceID     string     `json:"deviceId"      gorm:"size:256;not null;uniqueIndex:idx_dd_dep_dev;index"`
	Status       string     `json:"status"        gorm:"size:32;default:'pending';index"`
	DownloadedAt *time.Time `json:"downloadedAt"`
	CompletedAt  *time.Time `json:"completedAt"`
	Error        string     `json:"error"         gorm:"type:text;default:''"`
	CreatedAt    time.Time  `json:"createdAt"`
	UpdatedAt    time.Time  `json:"updatedAt"`
}

// AdminUser represents an operator account.
type AdminUser struct {
	ID           int64     `json:"id"          gorm:"primaryKey;autoIncrement"`
	Username     string    `json:"username"    gorm:"uniqueIndex;size:128;not null"`
	PasswordHash string    `json:"-"           gorm:"size:256;not null"`
	Role         string    `json:"role"        gorm:"size:32;default:'admin'"`
	CreatedAt    time.Time `json:"createdAt"`
}

// -- Request/Response DTOs --

type LoginRequest struct {
	Username string `json:"username" binding:"required"`
	Password string `json:"password" binding:"required"`
}

type LoginResponse struct {
	Token     string `json:"token"`
	ExpiresAt int64  `json:"expiresAt"`
}

type RegisterDeviceRequest struct {
	DeviceID       string `json:"deviceId"       binding:"required"`
	IPAddress      string `json:"ipAddress"`
	Hostname       string `json:"hostname"`
	OS             string `json:"os"`
	CurrentVersion string `json:"currentVersion"`
	GroupName      string `json:"groupName"`
}

type HeartbeatRequest struct {
	DeviceID       string `json:"deviceId"       binding:"required"`
	CurrentVersion string `json:"currentVersion"`
	Status         string `json:"status"`
}

type CheckUpdateResponse struct {
	HasUpdate   bool   `json:"hasUpdate"`
	ArtefactID  int64  `json:"artefactId,omitempty"`
	Version     string `json:"version,omitempty"`
	FileSize    int64  `json:"fileSize,omitempty"`
	SHA256Hash  string `json:"sha256Hash,omitempty"`
	DownloadURL string `json:"downloadUrl,omitempty"`
}

type CreateDeploymentRequest struct {
	ArtefactID      int64  `json:"artefactId"      binding:"required"`
	Name            string `json:"name"            binding:"required"`
	Description     string `json:"description"`
	TargetType      string `json:"targetType"      binding:"required"`
	TargetSpec      string `json:"targetSpec"`
	RolloutStrategy string `json:"rolloutStrategy"`
	MaxConcurrent   int    `json:"maxConcurrent"`
}

type PaginatedResponse struct {
	Data     interface{} `json:"data"`
	Total    int64       `json:"total"`
	Page     int         `json:"page"`
	PageSize int         `json:"pageSize"`
}

// -- Hooks --

func (d *Device) BeforeCreate(tx *gorm.DB) error {
	now := time.Now()
	if d.LastHeartbeat.IsZero() {
		d.LastHeartbeat = now
	}
	if d.CreatedAt.IsZero() {
		d.CreatedAt = now
	}
	if d.UpdatedAt.IsZero() {
		d.UpdatedAt = now
	}
	return nil
}